Scaling test of fermion actions in the Schwinger model

We discuss the scaling behaviour of different fermion actions in dynamical simulations of the 2-dimensional massive Schwinger model. We have chosen Wilson, hypercube, twisted mass and overlap fermion actions. As physical observables, the pion mass and the scalar condensate are computed for the above mentioned actions at a number of coupling values and fermion masses. We also discuss possibilities to simulate overlap fermions dynamically avoiding problems with low-lying eigenvalues of the overlap kernel

Fluid thrust control system

A pure fluid thrust control system is described for a pump-fed, regeneratively cooled liquid propellant rocket engine. A proportional fluid amplifier and a bistable fluid amplifier control overshoot in the starting of the engine and take it to a predetermined thrust. An ejector type pump is provided in the line between the liquid hydrogen rocket nozzle heat exchanger and the turbine driving the fuel pump to aid in bringing the fluid at this point back into the regular system when it is not bypassed. The thrust control system is intended to function in environments too severe for mechanical controls

Low computational complexity mode division multiplexed OFDM transmission over 130 km of few mode fiber

We demonstrate 337.5-Gb/s MDM-8QAM-OFDM transmission over 130 km of FMF. This confirms that OFDM can significantly reduce the required DSP complexity to compensate for differential mode delay, a key step towards real-time MDM transmission

Numerical Exploration of the RI/MOM Scheme Gauge Dependence

The gauge dependence of some fermion bilinear RI/MOM renormalization constants is studied by comparing data which have been gauge-fixed in two different realizations of the Landau gauge and in a generic covariant gauge. The very good agreement between the various sets of results and the theory indicates that the numerical uncertainty induced by the lattice gauge-fixing procedure is below the statistical errors of our data sample which is of the order of (1-1.5)%.Comment: 3 pages, 2 figures, Lattice2002(theoretical

Preconditioning of Improved and ``Perfect'' Fermion Actions

We construct a locally-lexicographic SSOR preconditioner to accelerate the parallel iterative solution of linear systems of equations for two improved discretizations of lattice fermions: the Sheikholeslami-Wohlert scheme where a non-constant block-diagonal term is added to the Wilson fermion matrix and renormalization group improved actions which incorporate couplings beyond nearest neighbors of the lattice fermion fields. In case (i) we find the block llssor-scheme to be more effective by a factor about 2 than odd-even preconditioned solvers in terms of convergence rates, at beta=6.0. For type (ii) actions, we show that our preconditioner accelerates the iterative solution of a linear system of hypercube fermions by a factor of 3 to 4.Comment: 27 pages, Latex, 17 Figures include

Control of rheumatoid arthritis with conventional disease-modifying antirheumatic drugs in a tertiary hospital in central South Africa

Background. Rheumatoid arthritis (RA) is a highly prevalent disease with a significant impact on morbidity and life expectancy. There is a paucity of literature relating to the current state of disease control in South Africa, and none on Free State Province.Objectives. To evaluate control of RA with conventional disease-modifying antirheumatic drugs (DMARDs) in the rheumatology outpatient department of Universitas Academic Hospital, Bloemfontein, and to determine the relative impact of various factors contributing to the prevention of disease control.Methods. A cross-sectional study was undertaken over a period of 8 months from December 2016 to August 2017 in the rheumatology outpatient department of Universitas Academic Hospital. Data were collected by means of information sheets and questionnaires completed by attending doctors. The information pertained to disease activity, possible factors contributing to poor control, and relevant demographic data.Results. Information was collected from 169 patients, and data analysis was performed on 161. The results revealed that RA was controlled in 34 patients (21.1%). Of the 127 patients with uncontrolled disease, 61 (48.0%) reported dispensing issues relating to poor drug availability. Seventy-two (56.7%) of the patients with uncontrolled disease were deemed to be on insufficient treatment for their disease state, of whom 33 (45.8%) also reported concomitant dispensing issues. Other factors such as transport/access problems, administrative issues, adverse events and poor compliance/insight contributed to the inadequate control of RA to a minor extent. In terms of monthly dispensing, 159 patients (98.8%) reported receiving all their DMARDs during the first month. The vast majority of these drugs were dispensed from Universitas Hospital. This figure decreased to 119 patients (73.9%) who received all their DMARDs during the second month, mostly from district units. Only 55.3% (n=89) of the patients reported receiving all of their DMARDs from their down-referral units.Conclusions. Control of RA at this institution is suboptimal compared with national and international standards. The main contributors to poor control appear to be problems relating to dispensing of medication and inadequate escalation of therapy by doctors. Most of the concern with the dispensing of medication lies with the poor availability of DMARDs in peripheral unit pharmacies. These factors are remediable and should be attended to

Ab initio study of canted magnetism of finite atomic chains at surfaces

By using ab initio methods on different levels we study the magnetic ground state of (finite) atomic wires deposited on metallic surfaces. A phenomenological model based on symmetry arguments suggests that the magnetization of a ferromagnetic wire is aligned either normal to the wire and, generally, tilted with respect to the surface normal or parallel to the wire. From a first principles point of view, this simple model can be best related to the so--called magnetic force theorem calculations being often used to explore magnetic anisotropy energies of bulk and surface systems. The second theoretical approach we use to search for the canted magnetic ground state is first principles adiabatic spin dynamics extended to the case of fully relativistic electron scattering. First, for the case of two adjacent Fe atoms an a Cu(111) surface we demonstrate that the reduction of the surface symmetry can indeed lead to canted magnetism. The anisotropy constants and consequently the ground state magnetization direction are very sensitive to the position of the dimer with respect to the surface. We also performed calculations for a seven--atom Co chain placed along a step edge of a Pt(111) surface. As far as the ground state spin orientation is concerned we obtain excellent agreement with experiment. Moreover, the magnetic ground state turns out to be slightly noncollinear.Comment: 8 pages, 5 figures; presented on the International Conference on Nanospintronics Design and Realizations, Kyoto, Japan, May 2004; to appear in J. Phys.: Cond. Matte

The amyloid β peptide Aβ (25–35) induces apoptosis independent of p53

AbstractApoptosis of neuronal cells apparently plays a role in Alzheimer’s disease (AD). The amyloid beta (Aβ) peptide derived from β-amyloid precursor protein is found in AD brain in vivo and can induce apoptosis in vitro. While p53 accumulates in cells of AD brain, it is not known if p53 plays an active role in Aβ-induced apoptosis. We show here that inactivation of p53 in two experimental cell lines, either by expression of the papillomavirus E6 protein or by a shift to restrictive temperature, does not affect apoptosis induction by Aβ (25–35), indicating that Aβ induces apoptosis in a p53-independent manner

Does training content matter? Differences between soft- and hard-skill trainings in transfer motivation

PurposeTransfer motivation has been identified as a pivotal factor influencing transfer of training. However, the role of training content has often been overlooked as explanatory variable for the rate of transfer motivation. This study aims to examine to what extent experiences in transfer motivation and its personal and contextual antecedents depend on whether the training content is soft or hard skill. To this end, this study used the perspective of the unified model of task-specific motivation.Design/methodology/approachA total of 1,122 trainees (462 soft skill and 660 hard skill) filled out a questionnaire representing the components of transfer motivation and its personal- and contextual antecedents. Data were analyzed by means of multi group structural equation modeling.FindingsThe results showed mean differences between soft- and hard-skill trainings in personal- and contextual antecedents of transfer motivation and for different types of transfer motivation. However, no differences in transfer intention were found.Practical implicationsThe outcomes provide insight as to what practitioners and trainers could do in training design and work environments to raise personal and contextual antecedents and to what extent a differentiation should be made between soft- and hard-skill trainings. This can eventually help them in raising transfer motivation among trainees.Originality/valueTo the best of the authors’ knowledge, this study is the first that examines whether experiences in personal and contextual antecedents of transfer motivation, transfer motivation and transfer intention differ for trainings consisting of different characteristics